I am studying signal processing at XX University Graduate School. Since the main language is PFX, there are not many built-in functions like in PAX, so knowing how to do these basic operations is very, very, very important when creating algorithms. I am learning a lot through this lecture. In particular, a lot of parts in PFX or CXX language numerical calculation books, Numerical Recipe, are similarly covered, so it is very helpful for understanding the subroutines themselves. Thank you.